1. Field of the Invention
The present invention relates to ear couplers or earphones that cover the ear to create a desired acoustic environment.
2. Background of the Invention
It is inherently difficult to determine hearing impairment in infants, since they cannot participate in traditional hearing tests which require subjects to indicate whether they can hear various sounds. However, if hearing impairment is not detected until the infant grows into a toddler or child, then the potential for long-term disability increases, since the child's language skills will have developed before remedial measures have been undertaken. The optimal time to screen for hearing impairment is immediately after birth, both because early detection allows for early treatment, and because parents often fail to bring their children in for later appointments.
Devices and methods have been developed to evaluate infant hearing by subjecting an infant to an aural stimulus, and then measuring the electroencephalographic or otoacoustic response to that stimulus. These devices and methods depend on the creation of the proper acoustic environment about the subject's ear, so that ambient noise does not interfere with the hearing evaluation, and so that the stimulus has the appropriate duration, amplitude, and frequency content.
To create the desired acoustic environment, earphones or ear couplers have been used. Information relevant to previous ear couplers can be found in U.S. Pat. Nos. 5,826,582, 4,930,520, and in U.S. patent application Ser. No. 09/395,799. Although many of these devices have worked well, they can sometimes become detached from the subject's head, because of the variable and irregular surfaces surrounding the ear, and because infants tend to move during testing. Additionally, with previous ear couplers, the assembly that houses the stimulus-producing transducer tends to tug the ear coupler away from the ear. Existing ear couplers are also relatively expensive to manufacture, in part because they require production or assembly of more than one part.
It is therefore desirable to construct an ear coupler that is better able to remain attached to the subject's head, and that is not subject to being tugged off the head by forces acting on the transducer housing. It is also desirable to design a one-piece ear coupler that can be inexpensively manufactured by injection molding or other suitable processes.